No, because it's not a myth. Eating healthy actually does requires a lot of energy & in many cases does cost more. If it doesn't cost more it's because you're going to be taking a lot out of the flavor department & you're going to be investing a lot of time shopping, preparing, storing & tracking costs. There is savings to be had in volume, but volume is hard to achieve when you're cooking for just 1 or 2 people.
Stating that "Italian peasants have been spending much less than $3 a meal for centuries" is silly on many counts. First this article is about $3 a day, not per meal($3/meal x 3 x 30 = $270 per person per month which seems more realistic). Second, you ignore currency inflation & the negatives of being a peasant. It's similar to saying it must be great to be a Chinese peasant because they can get rice for really cheap. Third, Italy is a small country that has a long history of quality food production, there is less focus on quality in the US & more on quantity. The US is a big country and the environment varies greatly from place to place. You might have a great farming community & your city might support farmers markets, but that doesn't mean that everyone has those facilities or even if they do that the products produced are actually cheap.
Part of the problem is that quality food has been relegated into a "gourmet" category which demands a higher price & profit margins than industrialized foods & even those industrialized foods aren't cheap in low volume. You will often see higher quality tomatoes on a Burger King burger than what's at your local supermarket going for $2.99/lb.
This is just a blog article, with one bland meal. I don't know how it even makes a scuff as far as destroying this "myth".